The new submodule handling depends on `is_git()` to be accurate to
decide whether it should handle submodules at all or not. Unfortunately,
`is_git()` treated "this directory does not have a git repository" and
"this repository should not be used for SHA/version/commit date info"
the same. This changes it to distinguish the two.

To clarify: ignore_get is set by default whenever channel == "dev", which it is by default whenever you're compiling locally. So basically everyone would hit this, not just people who had explicitly configured ignore_git.

Here's an example of an error this fixes:

```
$ x build
Updating only changed submodules
Submodules updated in 0.01 seconds
    Finished dev [unoptimized + debuginfo] target(s) in 0.17s
warning: x.py has made several changes recently you may want to look at
help: consider looking at the changes in `src/bootstrap/CHANGELOG.md`
note: to silence this warning, add `changelog-seen = 2` at the top of `config.toml`
Building stage0 std artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
    Finished release [optimized] target(s) in 0.16s
Copying stage0 std from stage0 (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu / x86_64-unknown-linux-gnu)
Building LLVM for x86_64-unknown-linux-gnu
detected home dir change, cleaning out entire build directory
running: "cmake" "/home/joshua/rustc3/src/llvm-project/llvm" "-G" "Ninja" "-DLLVM_ENABLE_ASSERTIONS=OFF" "-DLLVM_TARGETS_TO_BUILD=AArch64;ARM;BPF;Hexagon;MSP430;Mips;NVPTX;PowerPC;RISCV;Sparc;SystemZ;WebAssembly;X86" "-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=AVR" "-DLLVM_INCLUDE_EXAMPLES=OFF" "-DLLVM_INCLUDE_DOCS=OFF" "-DLLVM_INCLUDE_BENCHMARKS=OFF" "-DLLVM_ENABLE_TERMINFO=OFF" "-DLLVM_ENABLE_LIBEDIT=OFF" "-DLLVM_ENABLE_BINDINGS=OFF" "-DLLVM_ENABLE_Z3_SOLVER=OFF" "-DLLVM_PARALLEL_COMPILE_JOBS=48" "-DLLVM_TARGET_ARCH=x86_64" "-DLLVM_DEFAULT_TARGET_TRIPLE=x86_64-unknown-linux-gnu" "-DLLVM_ENABLE_ZLIB=ON" "-DLLVM_ENABLE_LIBXML2=OFF" "-DLLVM_VERSION_SUFFIX=-rust-dev" "-DCMAKE_INSTALL_MESSAGE=LAZY" "-DCMAKE_C_COMPILER=gcc" "-DCMAKE_CXX_COMPILER=g++" "-DCMAKE_ASM_COMPILER=gcc" "-DCMAKE_C_FLAGS=-ffunction-sections -fdata-sections -fPIC -m64" "-DCMAKE_CXX_FLAGS=-ffunction-sections -fdata-sections -fPIC -m64" "-DCMAKE_INSTALL_PREFIX=/home/joshua/rustc3/build/x86_64-unknown-linux-gnu/llvm" "-DCMAKE_ASM_FLAGS= -ffunction-sections -fdata-sections -fPIC -m64" "-DCMAKE_BUILD_TYPE=Release"
CMake Error: The source directory "/home/joshua/rustc3/src/llvm-project/llvm" does not exist.
Specify --help for usage, or press the help button on the CMake GUI.
thread 'main' panicked at '
command did not execute successfully, got: exit status: 1

build script failed, must exit now', /home/joshua/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/cmake-0.1.44/src/lib.rs:885:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
	finished in 0.783 seconds
Build completed unsuccessfully in 0:00:01
```

This reverts commit 30b82e0.

When determining which LLVM artifacts to download, bootstrap.py
calls: `git log --author=bors --format=%H -n1 -m --first-parent --
src/llvm-project src/bootstrap/download-ci-llvm-stamp src/version`.
However, the `-m` option has no effect, per the `git log` help:

> -m
> This option makes diff output for merge commits to be shown in the
> default format. -m will produce the output only if -p is given as
> well. The default format could be changed using log.diffMerges
> configuration parameter, which default value is separate.

Accordingly, this commit removes use of the -m option in favor of
`--no-patch`, to make clear that this command should never output
diff information, as the SHA-1 hash is the only desired output.
Tested using git 2.32, this does not change the
output of the command.

The motivation for this change is that some patched versions of git
change the behavior of the `-m` flag to imply `-p`, rather than to do
nothing unless `-p` is passed. These patched versions of git lead to
this script not working. Google's corp-provided git is one such example.

Stop creating a reference then immediately dereferencing it.

…wesleywiser

Add docs for raw-dylib to unstable book

…r=JohnTitor

Use hashbrown's `extend_reserve()` in `HashMap`

When we added `extend_reserve()` to our implementation of `Extend` for `HashMap`, hashbrown didn't have a version we could use. Now that hashbrown has added it, we should use its version instead of implementing it ourself.

Don't treat git repos as non-existent when `ignore_git` is set

The new submodule handling depends on `is_git()` to be accurate to
decide whether it should handle submodules at all or not. Unfortunately,
`is_git()` treated "this directory does not have a git repository" and
"this repository should not be used for SHA/version/commit date info"
the same. This changes it to distinguish the two.

To clarify: ignore_get is set by default whenever channel == "dev", which it is by default whenever you're compiling locally. So basically everyone would hit this, not just people who had explicitly configured ignore_git.

Here's an example of an error this fixes:

```
$ x build
Updating only changed submodules
Submodules updated in 0.01 seconds
    Finished dev [unoptimized + debuginfo] target(s) in 0.17s
warning: x.py has made several changes recently you may want to look at
help: consider looking at the changes in `src/bootstrap/CHANGELOG.md`
note: to silence this warning, add `changelog-seen = 2` at the top of `config.toml`
Building stage0 std artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
    Finished release [optimized] target(s) in 0.16s
Copying stage0 std from stage0 (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu / x86_64-unknown-linux-gnu)
Building LLVM for x86_64-unknown-linux-gnu
detected home dir change, cleaning out entire build directory
running: "cmake" "/home/joshua/rustc3/src/llvm-project/llvm" "-G" "Ninja" "-DLLVM_ENABLE_ASSERTIONS=OFF" "-DLLVM_TARGETS_TO_BUILD=AArch64;ARM;BPF;Hexagon;MSP430;Mips;NVPTX;PowerPC;RISCV;Sparc;SystemZ;WebAssembly;X86" "-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=AVR" "-DLLVM_INCLUDE_EXAMPLES=OFF" "-DLLVM_INCLUDE_DOCS=OFF" "-DLLVM_INCLUDE_BENCHMARKS=OFF" "-DLLVM_ENABLE_TERMINFO=OFF" "-DLLVM_ENABLE_LIBEDIT=OFF" "-DLLVM_ENABLE_BINDINGS=OFF" "-DLLVM_ENABLE_Z3_SOLVER=OFF" "-DLLVM_PARALLEL_COMPILE_JOBS=48" "-DLLVM_TARGET_ARCH=x86_64" "-DLLVM_DEFAULT_TARGET_TRIPLE=x86_64-unknown-linux-gnu" "-DLLVM_ENABLE_ZLIB=ON" "-DLLVM_ENABLE_LIBXML2=OFF" "-DLLVM_VERSION_SUFFIX=-rust-dev" "-DCMAKE_INSTALL_MESSAGE=LAZY" "-DCMAKE_C_COMPILER=gcc" "-DCMAKE_CXX_COMPILER=g++" "-DCMAKE_ASM_COMPILER=gcc" "-DCMAKE_C_FLAGS=-ffunction-sections -fdata-sections -fPIC -m64" "-DCMAKE_CXX_FLAGS=-ffunction-sections -fdata-sections -fPIC -m64" "-DCMAKE_INSTALL_PREFIX=/home/joshua/rustc3/build/x86_64-unknown-linux-gnu/llvm" "-DCMAKE_ASM_FLAGS= -ffunction-sections -fdata-sections -fPIC -m64" "-DCMAKE_BUILD_TYPE=Release"
CMake Error: The source directory "/home/joshua/rustc3/src/llvm-project/llvm" does not exist.
Specify --help for usage, or press the help button on the CMake GUI.
thread 'main' panicked at '
command did not execute successfully, got: exit status: 1

build script failed, must exit now', /home/joshua/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/cmake-0.1.44/src/lib.rs:885:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
	finished in 0.783 seconds
Build completed unsuccessfully in 0:00:01
```

I *believe* this regression was only introduced in rust-lang#87380, not rust-lang#82653. ``@petrochenkov`` can you check that this fixes the issue you encountered in rust-lang#82653 (comment) ?

r? ``@Mark-Simulacrum``

Suggest removing unnecessary &mut as help message

Closes rust-lang#68697

Document math behind MIN/MAX consts on integers

Currently the documentation for `[integer]::{MIN, MAX}` doesn't explain where the constants come from. This documents how the values of those constants are related to powers of 2.

Remove min_type_alias_impl_trait in favor of type_alias_impl_trait

r? ``@oli-obk``

…=dtolnay

SGX mutex is *not* moveable

Reverts the erroneous change in rust-lang#85029.

…n514

bootstrap.py: change `git log` option to indicate desired behavior

When determining which LLVM artifacts to download, bootstrap.py calls: `git log --author=bors --format=%H -n1 -m --first-parent --
src/llvm-project src/bootstrap/download-ci-llvm-stamp src/version`. However, the `-m` option has no effect, per the `git log` help:

> -m
> This option makes diff output for merge commits to be shown in the
> default format. -m will produce the output only if -p is given as
> well. The default format could be changed using log.diffMerges
> configuration parameter, which default value is separate.

Accordingly, this commit removes use of the -m option in favor of ~~`--diff-merges=off`~~ `--no-patch`, since no diff information is needed, and in fact the presence of a diff breaks the command. Tested using git 2.32, this does not change the output of the command.

The motivation for this change is that some patched versions of git change the behavior of the `-m` flag to imply `-p`, rather than to do nothing unless `-p` is passed. These patched versions of git lead to this script not working. Google's corp-provided git is one such example.

Stop creating a reference then immediately dereferencing it.

Stop creating a reference then immediately dereferencing it.

Fix ICE in `diagnostic_hir_wf_check`

Fixes rust-lang#87495. The [documentation for `ObligationCauseCode::WellFormed`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_infer/traits/enum.ObligationCauseCode.html#variant.WellFormed) says that

> it is always correct [...] to specify `WellFormed(None)`

instead of `WellFormed(Some(...))`, which seems to have caused the issue here, as `diagnostic_hir_wf_check` does not expect to be called with an associated constant and will ICE:

https://github.com/rust-lang/rust/blob/fd853c00e255559255885aadff9e93a1760c8728/compiler/rustc_typeck/src/hir_wf_check.rs#L131-L134

Therefore, I have changed `check_associated_item()` to pass a `WellFormed(None)` for associated constants.

r? ``@Aaron1011``